Road machine



March 19, 1935. Q Q A GUSTAFSQN 1,994,817

'- ROAD'MACHINE Filed Dec. 19, 1932 7 Sheets-Sheet l IN VEN TOR.

Car/ 19. Guszafson March 19, 1935. c. A. GUSTAFSON ROAD MACHINE Filed Dec. 19, 1952 7 Sheets-Sheet 2 IN V EN T 0R. Carl A. Gustaflson A TTORM March 19, 1935. c. A. GUSTAFS'ON ROAD MACHINE Filed Dec.

19, 1932 7 Sheets-Sheet 5 q ll h IN VEN TOR. Carl 4. Gustqfson March 19, 1935.

c. A, GUSTAFSON ROAD MACHINE Filed Dec. 19, 1932 7 Sheets-Sheet 4 March 19, 1935. c. A. GUSTAFSON ROAD MACHINE Filed Dec. 19, 1932 7 Sheets-Sheet 5 INVENTOR. Carl 1?. Gus-fat: on

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March 19, 1935. c. A. GUSTAFSON ROAD MACHINE Filed Dec. 19, 1952 7 Sheets-Sheet 6 R mm m m T I A Q .6 an w iki mm c C. A. GUSTAFSON ROAD MACHINE 7 Sheets-Sheet '7 Filed Dec. 19, 1932 INVEN TOR. Ca'r/ 14. Gusfdfson A TTORPE/Y.

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March 19, 1935.

atented Mar. 19, 1935 RUAD Mil Carl A. Gustafson, Peoria, Ml; assignor to Caterpillar Tractor 00., San llleandro, earn, a corporation of California Application Decembcrlll, 1932, Serial No. $417,886

14 Claims.

I The present invention relates to road machines and more particularly to the provision of snowplow attachments therefor.

Such attachments are known which are adapted tobe mounted on the front end of the road machine and which are used together with the blade of the machine to clear a path of sufiicient width to permit travel of vehicles in a single traverse of the roadway. Such attachments are usually provided with a. pivotal mounting and are moved from inoperative to operative position by lowering the front end of the plow. Such mounting means requires that the rear ends of the plow moldboards be positioned forwardly of the axis of pivotal movements of the snow-plow as the movement of the plow during adjustment must be entirely above the plane of the road surface.

It is often desirablethatthe size of the snow- 2 plow be made sufficiently large to clear the path during a single traverse of the road, and it has been found that a snow-plow of this size cannot be mounted to advantage. in the known method referred to above. This is true because as pointed out above, the entire plow must be located forwardly of the axis of pivotal movement thereof so that the connections which provide for the transmission of thrust to the plow and which provide for the adjustment of the plow must be made of substantially greater strength and size. This results in a more cumbersome attachment with unnecessary weight and which is much more difiicult to adjust. The invention disclosed'herein eliminates the disadvantages 'outlined above by providing .a mounting means for the snow-plow whereby the cutting edges thereof are maintained in substantially parallel relation to the surface of the roadway in operative and inoperative positions. This method of mounting does not substantially increase the length of the machine by increasing the size of the snow-plow and does not require the heavy connecting members which are necessary if the snow-plow is to be located a substantial distance forwardly of the front end of the machine. An additional advantage which is provided by this arrangement is in the decreased movement which is necessary in adjusting the plow from operative to inoperative position with a consequent saving in time and effort required for such adjustment. by providing a substantially vertical bodily movement of the plow, the nose of the plow is presented to the work before the diverging portions It is also to be noted that of the moldboard, which is not the case where a pivotalv adjustment is provided.

It is an object of the invention to provide improved mounting means for the snow-plow of a road machine. 5

Another object of the invention is to provide a snow-plow for a road machine which is of suflicient width to clear a path for the machine and which overlaps the front end of the machine.

Another object of the invention is to provide 10 a snow-plow for a road machine which is adjusted from operative to inoperative position by substantially vertical bodily movement.

Another object of the invention is to provide a parallel lift mechanism for the snow-plow of a road machine.

Another object of the invention is to provide power operated means for adjusting the snowplow of a road machine.

Another object of the invention is to provide mounting means for a snow-plow which is adapted to maintain the snow-plow in substantially parallel relation to the surface of the earth.

Another object of the invention is to provide mounting means for the snow-plow of a road machine which normally maintains the snow.- plow in a position parallel tothe surface'of the road but which is adapted to yield to permit the plow to clear an obstruction.

Another object of the invention is to provide mounting means for the snow-plow of a road 7 machine, including a plurality of parallel spaced unalined connections.

Another object of the invention is to provide a snow-plow adapted to be detachably mounted on the scarifier assembly of a road machine and having a substantially vertical bodily movement in response to operation of the scarifier adjusting mechanism.

Other objects will appear as the description progresses.

Y Description of figures Fig. 1 is a side elevation of a road machine with a snow-plow mounted thereon accordin to one form of the instant invention.

Fig. 2 is a partial plan view of the front end of the machine on the line 2-2 in Fig. 1.

Fig. 3 is a section on the line 3-3 in Fig. 2; 4 is a section on the line 44 in Fig. 2. 5 is a section on the line 5-5 inFig. 4. 6 is a section on the line G,-6 in Fig. 4. '7 is a view on the line 7-7 in Fig. 1. 8 is a. section on the line 88 in Fig. 2.

Fig. 9 is a diagrammatic view illustrating the plow raised to inoperative position.

Fig. 10 is a diagrammatic view illustrating the plow in operative position.

Figs. 11-14 illustrate a second form of the invention.

Fig. 11 is a side elevation of the front end of the machine with the snow-plow mounted according to the second form. of the invention, the right-hand moldboard of the plow being removed.

Fig. 12 is a plan view of the front end of the machine with the snow-plow mounted thereon according to the second form of the invention.

Fig. 13 is a diagrammatic view illustrating the inoperative position of the snow-plow mounted according to the second form of the invention.

Fig. 14 is a diagrammatic view illustrating the operative position of the snow-plow which is mounted according to the second form of the invention.

Description. of machine The invention disclosed herein is illustrated in connection with an automotive road machine, but is equally applicable to any other type of self-propelled vehicle.' The frame of the machine (Figs. 1 and 2) includes side channels 10, 11, which are symmetrical with respect to the longitudinal axis of the machine, having a slight convergence at their front ends (Fig. 2) which are connected by bolster 12. Adjacent their front ends said side channels 10, 11, are connected by cross member 13 (Figs. 2 and 3) in the form of a I-beam, the connections being reinforced by suitable gussets. Various other cross members are provided to brace the frame and to form supports, which are not essential to an understanding of the present invention.

The front end of the frame is supported on front wheels 16 which are steerable under the control of suitable steering mechanism controlled by steering wheel 1'? at the operators station which is located adjacent the rear end of the machine. The rear end of the frame is supported by driving wheels 21 (Fig.- 1) which are driven through suitable clutch and transmission mechanism from power unit 22 at the rear end of the frame. The controls for the power unit and the clutch and transmission mechanism are located at the operators station.

The road machine is provided with a plurality of earth engaging tools which are used in roadmaintenance work. Blade 26- is mounted revolubly in a framework including drawbars 27 having a universal draft connection at the front end of the frame. A plurality of adjusting mechanisms are provided for adjusting the blade vertically at either end, laterally with respect to the machine, and angularly with respect to the line of draft. Said adjusting mechanisms are operable by power-operated control mechanism including reversible clutch mechanism mounted in housing 28 at the operators station, having control levers 29 mounted thereon. A constantly running drive 30 is provided from power unit 22 to the reversible clutch mechanism in housing 28.

scarifier is provided with similar drawbars 36, 3'7 (Figs. 1 and '7) connected thereto at their rear ends and pivotally mounted on shaft 38 (Figs. 2 and '7) at their front ends. Said shaft 38 is mounted in laterally alined apertured bosses 39. 40 in bolster 12. Similar lift arms 41 (Fig. 1) are provided for adjustably supporting the scarifier from the frame and said lift arms are connected at their upper ends to similar cranks 42 which are oscillable to adjust the scarifier vertically. Each crank 42 is provided with arcuate gear segment 43 meshing with a pinion on cross shaft 44. Said shaft 44 is mounted at its ends on side channels 10, 11 and intermediate its ends in housing 45, which houses a suitable worm and worm wheel for driving said shaft. The worm and worm wheel are adapted to be operated by means including fork 46 from the power-operated control mechanism in housing 28. The telescopic shaft which serves to operate the scarifier lift when the scarifier is in use is shown connected to the adjusting means for the snowplow in Fig. 1, as described more specifically hereinafter.

The specific construction of the above described mechanisms forms no part of the instant invention and has not been described in detail. For a more complete description of such mechanisms, reference is hereby made to the application for Letters Patent of Oscar L. Starr, Serial No. 631,050, filed August 30, 1932.

The preferred form of the invention is disclosed in Figs. 1-10 and the snow-plow assembly illustrated includes an auxiliary frame which is detachably mounted on the frame of the machine and a snow-plow which is adjustably supported on the auxiliary frame.

The auxiliary frame for mounting the snowplow on the machine includes horizontal U-shaped channel 101 (Figs. 1 and 2) having its curved front end extending forwardly from the frame of the machine and its parallel sides extending rearwardly along side channels 10, 11. The ends of said channel 101 (Figs. 2 and 3) are secured by bolts 102 to the bent ends of cross strap 103 (Fig. 3) secured to the frame below cross member 13. At its right end strap 103 is secured to the lower flangeof side channel 11 by bolt 104, spacer 106 being interposed. The left end of strap 103 is similarly secured to side channel 10. Adjacent bolster 12 at the front end of the main frame similar brackets 111, 112 (Figs. 4 and '7) are riveted to the opposite sides of channel 101 and extend downwardly therefrom. Said brackets 111, 112 are provided with respective alined apertured bosses 113, 114 (Fig. 7) immediately below the sides of channel 101, which receive the ends of shaft 38. Washer 116 (Figs. 4 and 6) overlying the right end of shaft 38 is secured to bracket 112 by cap screw 117 and serves to position said shaft within said bracket. The left end of said shaft 38 is similarly held in bracket 111. Said brackets 111, 112 are interconnected below .bosses 113, 114 (Fig. 7) by tubular brace 121 welded thereto which serves to brace and space the lower ends of said brackets. Tubular cross brace 122 (Figs. 2 and '7) secured at its ends to the sides of channel 101 adjacent brackets 111, 112 serves to strengthen the auxiliary frame. From the foregoing description it is-seen that the auxiliary frame is detachably, mounted on the front end of the machine. v

The snow-plow is supported adjustably on said auxiliary frame, a thrust connection being provided therebetween. The snow-plow is V-shaped and includes forwardly converging concave moldboards 126 (Figs. 2 and 7) having a welded connection at their forward ends, longitudinal curved runner 127 being welded between said moldboards at-the bottom. Cutting edges 128 (Figs. 2 and 5) are detachably secured to the lower edges of said moldboards and abut runner 127 at their forward ends. welded along the upper edges of said moldboards Bracing angles 129 (Figs. 4 and 7) are and bracing angles are welded adjacent the lower edges thereof. Said moldboards are connected adjacent their rear ends by cross frame 131 (Fig. 7) including horizontal angles 132, 133 riveted to vertical curved end pieces 134 welded to said moldboards. Spaced vertical angles 135 are riveted to said angles 132, 133, the connections being strengthened by suitable gussets.

A thrust connection is provided between the snow-plow and the auxiliary frame which serves to urge the snow-plow downwardly into contact with the surface being cleared of snow. Thrust frame 139 includes side angles 140, 141 (Figs. 2

and 7) which converge forwardly to connection 142 being bolted thereto. Intermediate their ends cross strap 143 is riveted to said angles, the connections being strengthened by suitable gussets. Brackets 144, 145 (Figs. 4 and 7) bolted to the rear ends of said angles 140, 141 are apertured to receive shaft 146 having its ends mounted in apertured bosses 147, 148, respectively, in the lower ends of said frame brackets 111, 112. Said shaft 146 is pinned in boss 147. Thus the rear end of the thrust frame is pivotally connected to the auxiliary frame. The front end of the thrust frame (Fig. 4) is lower than the rear end thereof when the plow is in operative positionand has a pivotal connection with the snow-plow. Connection 142 has apertured boss 151 which receives pin 152 having its ends suitably secured in upright ears 153 (Fig. 2) of bracket 154. Bracket 154 is bolted to horizontal plate 155 (Figs. 4 and 7) welded to moldboards126. Vertical cross brace 156 is welded to plate 155 and to said moldboards. It isbelieved apparentfrom the foregoing description that the, thrust frame urges the snowplow forwardly and downwardly.

A parallel lift linkage is provided for supporting the snow-plow adjustably from the auxiliary frame. The said linkage includes three similar triangularly spaced connections which serve to maintain the plow resiliently in adjusted position while permitting it to rise in passing over obstructions. Front connection 160 (Fig. 4) includes rod 161 pivotally connected to bellcrank 162 at its upper end, and having collar 163 detachably secured to its lower end below apertured boss 164 of bracket 142. Said rod passes through the aperture in boss 164 which is urged against collar 163 by spring 166 surrounding said rod and held between said boss 164 and collar 167 pinned on said rod by bolt 168 which is adapted to be inserted into any one of a plurality of apertures 169 in said rod whereby the tension on the spring may be adjusted. Bellcrank 162 is pivotally supported in bracket 171 mounted on the. forward end .of U-shaped channel 101. Thus a resilient connection is provided between the auxiliary frame and the snow-plow adjacent the forward end thereof, while the pivotal mounting of the bellcrank provides a means for adjusting the front end of the snow-plow vertically.

Thecross frame connecting the snow-plowvided with oil fittings 179. Connection 181 (Fig.

7) similarly connects bracket 182 on left-hand vertical angle 135 and am 183 clamped and keyed on the left end of said shaft 176. Said arms 174 and 183 are similar, and are parallel to each other and the lower arm of bellcrank 162, as seen in Fig. 4. Centrally of shaft 176 and in longitudinal alinement with bellcrank 162 (Figs. 2 and 4) arm 184 is mounted on said shaft and is positioned substantially at right angles to said arms 174, 183, in parallel relation with the upper arm of bellcrank 162. Rod 186 (Figs. 2 and 4) ispivoted at its rear end on pin 187 between the forked ends of arm 184, and has threaded engagement at its front end with yoke 188 pivoted to the upper arm of bellcrank 162. Clamping bolt 189 is provided in yoke 188 whereby the split threaded portion of said yoke may be clamped tightly in engagement with rod 186 to maintain the adjustment between arm 184 and bellcrank 162.

From the foregoing description it is seen that the parallel resilient connections from the auxiliary frame to the snow-plow serve to raise or lower the snow-plow in parallel relation to the surface of the earth as arm 184 and bellcrank 162 are oscillated simultaneously. Power-operated means are provided for operating the parallel lift linkage to adjust the snow-plow to operative or inoperative position, and said means comprises an adjustable telescopic connection between the parallel lift linkage and the frame of the machine.

The telescopic connection includes shield 191 (Figs. 2 and 8) having its forked forward end pivoted on pin 187 (Fig. 2; and having its rear end threaded within nut 192 (Fig. 8) and clamped therein by means of clamping bolt 193. Nut 192 is internally threaded and receives screw 194 1 having its reduced rear end mounted rotatably in connection 196 being held therein by fork 197, suitable washers 198 being provided at each side of connection 196. The threaded portion of screw 194 which is to the left of nut 192 is protected by shield 199 mounted in the rear end of said nut in the same manner that shield 191 is mounted in the front end thereof. Nut 192 is provided with oil fitting 200 whereby lubricant is introduced therein. Connection 196 (Figs. 2 and 3) is provided with integral trunnions 201 which are mounted in apertured bosses 202 in similar brackets 203 on I-beam 13. Right-hand trunnion 201 (Fig. 3) is bored and has a suitable oil fitting mounted therein. Boltv 204 and spacer 206 serve to brace said brackets 203 and maintain them in the correct spaced relation. From the foregoing description it is seen that rotation of screw 194 causes nut 192 to travel therealong, thereby oscillating arm 184 and bellcrank 162 to correspondingly adjust the snow-plow. Fork 197 (Fig. 1) forms part of universal joint 207 connecting screw 194 to telescopic shaft 208. Said shaft 208 is driven through universal joint 209 from a reversible clutch mechanism in power control clutch housing 28 whereby the snowplow may be raised from operative to inoperative position by power derived from the motor 22. This operation is clearly illustrated diagrammatically in Figs. 9 and 10. In Fig. 9 the snowplow is raised to inoperative position, bellcrank 162 and arms 184, 174 having been-oscillated to their furthest counter-clockwise position by travel of nut 192 along screw 194. In Fig. 10 the telescopic connection is extended whereby bellcrank 162 andarm 184 are oscillated to their furthest clockwise position to place the snow-' triangular relation and are adjusted simultaneously, the cutting edges of the snow-plow are maintained parallel to the surface of theroad.

In the second form of the invention, the parallel lift linkage is operated from the scarifier adjusting mechanism and the snow-plow is mounted on the scarifier drawbars. The construction of the snow-plow illustrated in Figs. 11 to 14 is identical with that heretofore described and need not be referred to specifically. Similar brackets 301, 302 (Figs. 11 and 12) are bolted to respective scarifier drawbars 36 and 37 adjacent their pivotal connection with shaft 38 mounted in bosses 39 and 40 in bolster 12. The lower ends of said brackets 301, 302 are apertured to receive shaft 304 which pivotally supports the rear end of thrust frame 139 (Fig. 11) heretofore described. Bars" 306, 307 (Fig. 12) are secured at their rear ends to respective brackets 301, 302 and converge forwardly to connection 308 to which they are bolted. The forked forward end of connection 308 receives pin 309 to which resilient connection 311 is pivoted. Said connection 311 is similar to connection 160 heretofore described and ,is similarly connected at its lower end to bracket 142. Said connection 311 serves to adjust the front of the snow-plow.

Resilient connections 312, 313 (Figs. 11 and 12), similar to connection 311, are attached at their lower ends to upper cross angle 132 adjacent its ends and are pivoted at their upper ends to similar longitudinal bars 316, 317. Said connections 312, 313 are parallel, as are bars 316, 317. Said bars 317 are pivotally mounted rearwardly of their centers on pins 318 in brackets 319, 321, respectively, bolted on respective side channels 10, 11; At their rear ends said bars 316, 317 are pivoted to straps 322, 323, which are pivoted at their respective lower ends to drawbars 36, 37. As described hereinbefore, said drawbars are vertically adjustable by lift arms 41, cranks 42 and gearing in'housing 45. The gearing in housing 45 is operated by telescopic shaft 208 (Fig. 1) which is connected to fork 46 when the snowplow is mounted on the machine according to the second form of the invention.

Figs. 13 and 14 illustrate diagrammatically the adjustment of the snow-plow in operative and inoperative position. For convenience in description, only the linkage associated with righthand drawbar 37 will be referred to in connection with the diagrammatic views, it being understood that the left-hand linkage operates similarly. In Fig. 13, crank 42 is rotated in its furthest clockwise direction, lift arm 41 is lowered, and drawbar 37 is oscillat ed in a counter-clockwise direction, as is bar 307, secured thereto. Thus the scarifier drawbar through bar 307 serves to raise the front end of the plow. Bar 317 connected to drawbar 37 by a strap 323 is also oscil lated in a counter-clockwise direction and serves to raise the rear end of the snow-plow. The different lengths of the lever arms of bar 317 and the offset relation of the pivot point therefor form the pivot point for drawbar 37, and bar 307 serves to maintain the cutting edges of the snowplow in a parallel relation to the surface of the road. In Fig. 14 crank 42 is rotated to its furthest clockwise position and the scarifier drawbars are raised to lower the snow-plow to operative position. It is to be noted that the triangularly spaced resilient connections of the second form of the invention, like those of the first, serve to maintain the cutting edges of the snow-plow parallel to the surface of the road.

I, therefore, claim as my invention:

1. In a self-propelled road machine, a main frame having steerable front supports and driving rear supports, a snow-plow disposed in front of said machine adapted to clear a path for said front and rear supports, and means for operatively mounting said snow-plow. on said frame including a thrust frame pivotally connected to said snow-plow and to said frame, and a parallel lift linkage mounted on said frame and supporting said snow-plow.

2. In a self-propelled road machine, a main frame having steerable front supports and driving rear supports, a snow-plow disposed in front of said machine adapted to clear a path for said front and rear supports, and means for operatively mounting said snow-plow on said frame in-' cluding a thrust frame pivotally connected to said snow-plow and to said frame, a parallel lift linkage mounted on said frame and supporting said snow-plow, and power-operated means for operating said linkage to adjust said snow-plow vertically, said linkage being adapted to maintain a parallel relation between the surface of the ground and said snow-plow in any adjusted position thereof.

3. In a self-propelled road machine, a main frame having steerable front supports and driv- 1 ing rear supports, a snow-plow disposed in front of said machine adapted to clear a path for said front and rear supports, and means for operatively mounting said snow-plow on, said frame including a thrust frame pivotally connected to said snow-plow and to said frame, a parallel lift linkage mounted on said frame and supporting said snow-plow, and power-operated means including linkstelescoped one within another for operating said linkage to adjust said snow-plow vertically, said linkage being adapted to maintain a parallel relation between the surface of the ground and said snow-plow in any adjusted position thereof.

4. In a self-propelled road machine, a main frame having steerable front supports and driving rear supports, said main frame including longitudinal side members, a bolster connecting the front ends of said side members, a cross member connecting said side members adjacent their front ends, an auxiliary frame detachably secured to said main frame comprising a U- shaped member having its ends connected to said main frame adjacent said cross member, a shaft mounted in said bolster, a pair of brackets secured to said U-shaped member and mounted on said shaft adjacent the ends thereof, a second shaft connecting said brackets, a snow-plow comprising rearwardly diverging moldboards, and a cross frame connecting said moldboards adjacent the rear ends thereof, a thrust frame pivotally secured at its front end to said plow and at its rear end to said second shaft, a third bracket mounted on said U-shaped member at the front end thereof, a bellcrank pivotally mounted in said third bracket, a connection from the lower arm of said bellcrank to said thrust frame adjacent the pivotal connectionv thereof to said snow-plow, a third shaft pivotally mounted in said pair of brackets, a pair of arms on the ends of said third shaft, connections from said arms to said cross frame adjacent the ends thereof, a third arm on said third shaft longitudinally alined with said bellcrank, an adjustable connection between said third arm and the upper arm of said bellcrank whereby a parallel relation ismaintained therebetween, a fourth bracket on said main frame cross member, links telescoped one within another connecting said bracket and the upper arm of said bellcrank, and means for adjusting said links telescopically to adjust said snow-plow vertically.

5. In a vehicle, a frame, a snow-plow, a plurality of resilient substantially parallel connections from said snow-plow to said frame arranged in spaced relation, and means for adjusting said plow vertically with. respect to said frame comprising a linkage adapted to impart substantially equal movements to each of said connections, said connections being adapted to yield to allow movement of said plow over obstructions without operation of said adjusting means.

6. The combination with a road machine having a scarifier assembly adjustably connected with the front end thereof, and adjusting means therefor, of a snow-plow, and means for mounting said snow-plow on said scarifier assembly including a lever system connected to said snowplow at a plurality of spaced points and operable by said adjusting means to adjust'said snow-plow vertically to position the cutting edges thereof in any one of a plurality of planes.

7. The combination with a road machine having a scarifier assembly adjustably connected with the front end thereof, and adjusting means therefor, of a snow-plow, and means for mounting said snow-plow on said scarifier assembly including a lever system resiliently connected to said snow-plow at a plurality of spaced unalined points and operable by said adjusting means to adjust said snow-plow vertically to position the cutting edges thereof in any one of a plurality of parallel planes.

8. In a road machine, a frame, a snow plow, a thrust frame movably connected to said plow and to said frame, and means for adjusting said plow substantially vertically with respect to said frame while maintaining a substantially parallel relationship between said plow and the surface of the earth, said means including a parallel lift linkage having a plurality of resilient connections, one of said resilient connections having one point of connection with said thrust frame and another point of connection with said first mentioned frame, and another of said resilient connections having one point of connection with said plow and another point of connection with said first mentioned frame.

9. In a road machine, a frame, a V-shaped snow plow, a thrust frame having one end movably connected to said plow adjacent the front of said plow and another end movably connected to said frame, and means for adjusting said plow with respect to the ground, said means including a plurality of lift connections from said plow to said frame, one of said connections having a point of connection on said thrust frame adjacent the end of said thrust frame connected with the front of said plow.

-10. In a road machine, a frame, a V-shaped snow plow, a thrust frame having one end movably connected to said plow adjacent the front of said plow and another end movably connected to said frame, and means for adjusting said plow with respect to the ground, said means including a plurality of resilient lift connections from said plow to said frame, one of said resilient connections having a point of connection with said plow adjacent the front thereof, and the remaining of said resilient connections being laterally spaced and having each a point of connection with said plow rearwardly of the front resilient connection.

11. In a road machine, a frame, a V-shaped snow plow, a thrust frame having one end movably connected to said plow adjacent the front thereof and another end movably connected to said frame, and means for adjusting said plow substantially vertically with respect to said frame while maintaining a substantially parallel relationship between said plow and the surface of the earth, said means including a parallel lift linkage having a plurality of connections from said plow to said frame, one of said connections having a point of connection with said plow adjacent the front thereof, and the remaining of said connections being spaced laterally and having each a point of connection with said plow rearwardly of the front connection.

12. In a road machine, a main frame, an auxiliary frame detachably secured to said main frame adjacent an end of said main frame, a snow plow, and means for mounting said plow on said auxiliary frame for movement with respect to the earth, said means including a parallel lift linkage having a plurality of resilient connections from said plow to said auxiliary frame.

13. In a road machine, a main frame, an auxiliary frame detachably secured to said main frame adjacent an end of said main frame, a V-shaped snow plow, a thrust frame having one end pivotally connected to said plow adjacent the front of said plow and another end pivotally connected to said auxiliary frame, a plurality of bellcranks pivotally mounted on said auxiliary frame, one of said bellcranks being adjacent an end of said auxiliary frame and the remaining of said bellcranks being disposed in lateral spaced relationship at the rear of said one bellcrank, means interconnecting said bellcranks for movement together, and resilient connecting means between an arm of each bellcrank and said plow, one of said connecting means being connected with said plow adjacent the front of said plow and the remaining of said connecting means being disposed rearwardly of said front connecting means.

1 1. In a road machine, a frame, a ll-shaped snow plow, a reenforcing cross-frame secured to said plow and spaced from the front of said v, a thrust frame having one end movably connected to said plow adjacent the front of said plow and another end movably connected to said frame, a lift linkage connected to said thrust frame adjacent the front of said plow, and a pair of additional laterally spaced lift linkages, each of said additional lift linkages having a point of connection with said crossframe.

CARL A. GUSTAFSON. 

